I tried a few manual requests by email a couple years back, they all got straight up ignored. I ended up paying for a removal service, and I’ve had better luck with them, I think they claim I’ve been removed from 70% of the ~150 brokers they target; I spot checked a few of the big ones to confirm.
It is worth noting that between county property tax records and voter registrations both being public (in the US), there isn’t much hope of actually keeping this data private. But I do get fewer spam calls than I used to, so that’s something.
No not all of them, just a few of the public databases like peoplefinders and whitepages.